Two new COVID-19 vaccines have recently made news. China’s Sinovac coronavirus vaccine was shown to be 78% effective against Covid-19 in Brazilian trials and offers total protection against severe cases of the disease. This raised hopes it could be used to immunize much of the developing world, and serve as an alternative to the AstraZeneca-Oxford vaccine which has showed much lower efficacy.
Brazil’s Butantan Institute, a São Paulo-based research center that conducted the CoronaVac Phase 3 trials, said Thursday that none of the volunteers who took the vaccine developed severe cases of Covid-19. Over 12,000 health workers took part in Phase 3 trials in Brazil, the first country to complete tests of Sinovac’s vaccine. The trials were moved to Brazil because China now has so little COVID-19 it was difficult to test the vaccine there!
“It’s a great result,” said Luiz Carlos Dias, part of a Covid-19 task force of researchers at the University of Campinas in São Paulo state. “If it can prevent severe cases, hospitalizations, deaths, it will help get us out of this pandemic.” Brazil now has 200,000 COVID-19 deaths, second only to the U.S.
CoronaVac’s vaccine is less effective than those from Moderna Inc. and Pfizer/BioNTech SE that have efficacy rates of 94.5% and 95% in testing, respectively. But CoronaVac can be kept in a standard refrigerator making it easier and cheaper to transport and store in less developed countries.
Unlike the vaccines Moderna and Pfizer developed with a new technology using genetic codes, CoronaVac uses weakened forms of the virus to induce an immune response—a more traditional method that tends to produce lower efficacy rates, researchers said.
In a report in the WSJ Prashant Yadav, a global health specialist at Washington-based think tank Center for Global Development, said 78% is a high enough rate for many developing countries to consider using the vaccine and potentially good enough for the World Health Organization to consider incorporating CoronaVac into its global distribution system.
“There are a large number of developing countries that haven’t been able to secure supplies,” he said. “This could become a very viable option for them.”
Butantan is building a factory to produce up to 1 million doses of CoronaVac a day and said it is now requesting authorization for emergency use of the vaccine in Brazil. It also has an agreement with Sinovac to become the vaccine’s distributor in Latin America and is in talks to start shipping CoronaVac to Argentina, Bolivia, Colombia, Honduras, Peru, and Uruguay as of May.
Sinovac’s vaccine was approved for emergency use by Beijing in July, along with two other vaccine candidates by Chinese state-owned vaccine maker Sinopharm which reported its vaccine to be 79% effective, based on interim analysis.
In contrast to the good news for Sinovac, a coronavirus vaccine developed by the German Centre for Infection Research (DZIF) and vaccine maker IDT Biologika did not prompt the hoped-for immune reaction in early-stage testing on humans, trial investigators at university hospital Hamburg-Eppendorf (UKE) said on Friday.
Further testing has been suspended until the cause for the weak immunogenicity in the Hamburg trial involving 30 volunteers has been established, UKE said in a statement, adding that the vaccine was well tolerated.
IDT said in November it was hoping to be able to apply for regulatory approval at the end of 2021. That obviously won’t happen now.